Bush Senior in Intensive Care, Wife Barbara in Hospital

Former president George H.W. Bush was admitted to an intensive care unit Wednesday suffering from pneumonia, highlighting concerns about the health of a political dynasty's patriarch just as a new U.S. leader prepares to enter office.

Bush, 92, was initially hospitalized Saturday for shortness of breath, but was moved to intensive care "to address an acute respiratory problem stemming from pneumonia," Bush's office said in a statement.

"Doctors performed a procedure to protect and clear his airway that required sedation."

Early Wednesday, Bush's wife, the former first lady Barbara Bush, 91, also was admitted to Houston Methodist Hospital "as a precaution after experiencing fatigue and coughing," it said.

"President Bush is stable and resting comfortably in the ICU, where he will remain for observation," said the statement, posted by Bush spokesman Jim McGrath on Twitter.

President Barack Obama, who was holding his final news conference before Donald Trump is sworn in as his successor Friday, said he has been in touch with the Bush family and that he and First Lady Michelle Obama were sending their prayers.

"They have not only dedicated their lives to the country, but they have been a constant support and good counsel for Michelle and me," Obama told reporters.

"They are as fine a couple as we know."

Former president Bill Clinton tweeted: "41 and Barbara -- thinking about you both and sending wishes for a speedy recovery. Love, 42."

Incoming vice president Mike Pence tweeted that he was keeping Bush "in our thoughts and prayers."

Bush, who served as president from 1989 to 1993, is the oldest of the four living former U.S. presidents and uses a wheelchair. He has seemed frail in recent public appearances.

- 'In spirit' -

On January 10, he wrote Trump a warm personal letter offering regrets that he and his wife would not be able to make it to Friday's presidential inauguration in Washington.

"My doctor says if I sit outside in January, it likely will put me six feet under. Same for Barbara," Bush wrote.

"So I guess we're stuck in Texas. But we will be with you and the country in spirit."

In July 2015, Bush was treated in a Maine hospital after falling and breaking a bone in his neck. The previous December, he was admitted to Houston Methodist Hospital for breathing problems.

He was treated at the same facility in November 2012 for bronchitis, spending nearly two months in the hospital.

George Herbert Walker Bush was born June 12, 1924 in Milton, Massachusetts to a wealthy New England political dynasty, the son of Prescott Bush, a successful banker and US senator for Connecticut.

He deferred his acceptance to Yale University in order to join the U.S. Navy and head off to World War II, before marrying Barbara and heading to west Texas to crack into the oil business.

As a rising political star, he served in the U.S. House of Representatives, as US ambassador to the United Nations, and director of the Central Intelligence Agency before becoming vice president to Ronald Reagan for eight years.

As president, Bush steered the United States through the end of the Cold War and drove Iraq from Kuwait, only to be denied a second term over a weak economy.

Bush is father to former president George W. Bush (2001-2009) and former Florida governor Jeb Bush, who was a contender in the 2016 Republican presidential primary.

Barbara Bush has been protective of her powerful family. But she made headlines when she suggested that Jeb not run for the office, even though he was the "best qualified man" to serve.

"I think it's a great country, there are a lot of great families, and it's not just four families or whatever," she told NBC's Today show in 2013 when asked if she wanted to see Jeb, who was then governor, make a White House run.

"There are other people out there that are very qualified, and we've had enough Bushes."